Several devices have been utilized to externally compress blood vessels in various parts of the body for the purpose of reducing or stopping the flow of blood through said vessels. A tourniquet is a simple device used around a limb which, when tightened, reduces or stops arterial blood flow to the distal portions of the limb thereby minimizing hemorrhaging from wounds or punctures in the vessels. For medical procedures, tourniquet-type devices have been specifically designed to prevent bleeding through a cannulation or needle puncture in a vessel in a patient's forearm. U.S. Pat. No. 5,269,803 by Geary et al discloses a strap that encircles the forearm with a pressure pad that applies compression over the vessel to prevent bleeding through the puncture. Other devices that include a strap to prevent bleeding through a puncture site include: U.S. Pat. No. 4,182,338 to Stanulis; U.S. Pat. No. 4,005,709 by Laerdal; U.S. Pat. No. 3,954,109 by Patel; and U.S. Pat. No. 3,586,001 by Sanderson.
Several devices have improved upon the basic tourniquet by applying pressure to only selected points instead of around the entire circumference of the limb, for example: U.S. Pat. No. 6,647,986 by Korotko et al; U.S. Pat. No. 5,728,120 by Shani et al; U.S. Pat. No. 5,601,597 by Arrowood et al; U.S. Pat. No. 5,569,297 by Makower et al; U.S. Pat. No. 5,295,996 by Blair; U.S. Pat. No. 5,234,459 by Lee; U.S. Pat. No. 4,760,846 by Kelly et al; U.S. Pat. No. 4,557,262 by Snow; U.S. Pat. No. 3,570,496 by Sachs; U.S. Pat. No. 2,271,927 by Saighman; and U.S. Pat. No. 1,473,041 by Henderson; and U.S. patent application Ser. No. 12/737,087 by Benz. Each of these devices includes a strap for encircling a patient's limb, and pressure pads or similar devices to apply compression to stop the blood flow through the target vessels in the limb. A device called the TR Band marketed by Terumo, as described in U.S. Pat. No. 7,498,477 by Wada, utilizes a wrist-encircling tourniquet-type strap that applies compression by means of an inflatable bladder.
Other devices are known to the inventors, which, although they do not take the form of a tourniquet or derivative device, help achieve hemostasis in blood vessels. Examples include: U.S. Pat. No. 5,304,186 by Semler, et al; U.S. Pat. No. 4,742,825 by Freund et al; U.S. Pat. No. 4,572,182 by Royse; U.S. Pat. No. 4,233,980 by McRae et al; U.S. Pat. No. 3,779,249 by Semler. These disclose mechanical or pneumatic means of applying compression over a blood vessel for the purpose of allowing a clot to form, thereby enabling hemostasis and corollary cessation of bleeding. Features noted in this art are: i) the use of clamping or inflatable bladder mechanisms to apply compression to the body surface overlying a target blood vessel and not all vessels in or leading to the extremity, and ii) the incorporation of features to gradually reduce compression and permit direct visual observation of a surface wound or puncture site leading to the target vessel close to the point of compression.
Additional patents disclose straps that are used in combination with pressure pads for therapeutic purposes other than occluding the flow of blood: U.S. Pat. No. 5,372,575 by Sebastian; U.S. Pat. No. 5,312,350 by Jacobs; U.S. Pat. No. 5,135,473 by Epler et al.; U.S. Pat. No. 5,078,728 by Giarratano; U.S. Pat. No. 4,590,939 by Sakowski; U.S. Pat. No. 4,479,495 by Isaacson; U.S. Pat. No. 4,323,232 by Terpening; U.S. Pat. No. 4,308,861 by Kelly; U.S. Pat. No. 4,243,028 by Puyana; and U.S. Pat. No. 519,894 by Schutz et al.
The prior art teaches that compression applied externally, i.e. on the body surface and over a target blood vessel slows the blood flow such that a clot can form so that normal hemostasis may occur. The prior art further teaches the value of: i) enabling visual access to the puncture or wound site on the body surface, and ii) providing preferential compression over a target vessel, so that arterial flow to or venous return from an extremity, for example a hand, are important attributes of a device having the purpose of achieving hemostasis following cannulation.
One requirement, well-known to clinical practitioners, which arises following medical procedures involving an arterial puncture, for example, radial artery catheterization, is the necessity to gradually release compression over the vessel to gradually increase blood flow while not disturbing the clot formed during the hemostasis process. Devices used for hemostasis, for example, as described by Semler, provide a means of gradually reducing compression. While there are many references that disclose the broad concept of using a strap with a pressure pad to stop the flow of blood through an arterial puncture wound located on the arm or wrist, none of these devices provides a convenient, low-cost, user-controlled, easily-adjustable means of: i) rapidly applying compression to a blood vessel while the cannula is removed, and ii) adjusting the amount of compression being applied to the point of compression in consistent, fine increments without releasing the fastening mechanism of the apparatus so as to avoid the risk of a bleeding complication due to a sudden unexpected absence of compression, and iii) quickly releasing compression and removing the device from the patient, and iv) integrating the adjustment and fastening means to enhance ease of use, and v) enabling distal blood flow through adjacent blood vessels, for example, distal blood flow through the ulnar artery and venous return from the hand. Although Wada describes an adjustable device, it lacks an integrated means of securing, adjusting and quickly releasing the device within a single structure of the device. Although Benz describes an adjustable device, it does not provide a low cost of manufacture due to its multiple components.
In addition, as initially described by Samir Pancholy, MD in the PROPHET Study of 2007 (Pancholy et al, Catheter Cardiovasc Interv. 2008 Sep. 1; 72(3):335-40. doi: 10.1002/ccd.21639), continued perfusion through the radial artery during the period in which external compression is applied for the purpose of achieving hemostasis at the arteriotomy and puncture site is required in order to reduce the incidence of chronic radial artery occlusion, a not-uncommon complication of radial access. He coined the term, “patent hemostasis” to refer to patency of the radial artery during the hemostasis period and shows that adjusting compression to permit such patent hemostasis helps to avoid chronic radial artery occlusion. Therefore, a need exists for a low-cost, easily adjustable, secure vascular compression device.